Acenaphthylene, acenaphthene, and vinylnaphthalenes are valuable precursors for the formation of pitch-based carbon fibers. Their use can improve carbon fiber processing and properties. Acenaphthene and acenaphthylene are also suitable for oxidation to 1,8-naphthalene dicarboxylic acid which in turn can be used to make polyester products.
Hussman et al. U.S. Pat. No. 4,740,647, of which the present application is a continuation-in-part, discloses that 1-ethylnaphthalene can be converted to acenaphthene or acenaphthylene using copper aluminum borate catalyst.
Satek U.S. Pat. No. 4,590,324 discloses dehydrogenation of alkylaromatics containing at least two carbons in at least one alkyl group to alkenylaromatics using a catalyst comprising metallic copper on a support comprising aluminum borate, the patent does not disclose or suggest use of the catalyst for cyclization of alkyl side chains separated by the bridging carbon of a polynuclear aromatic compound, as described in the present invention, to afford compounds having at least one more ring than the starting compound.
McArthur U.S. Pat. No. 4,024,171 discloses the use of catalysts comprising an aluminum borate support post treated with copper. Among the reactions disclosed for this catalyst are dehydrocyclization reactions. However, McArthur does not disclose crystalline copper aluminum borate having the unique x-ray diffraction pattern which is characteristic of the catalyst used in the present invention.